My ex boyfriend keeps sending me emails?

Okay, 2months ago spam sent something to my ex and others on my contact list. I never sent it but it was from me. That was only once. Now, my ex is sending me spam emails, like back to back. Its kind of p*ssing me now.We are not talking. We left off on bad terms.

What should I do?

Could it be on purpose?

Updates:

The reason why I ask is because out everyone I know its him. I never had anyone send me spam except.